Various objects, including mineral resources such as iron ore and limestone, are conveyed by a conveyor belt.
When being conveyed by the conveyor belt, the objects to be conveyed are fed onto an upper cover rubber of the conveyor belt from a hopper or another conveyor belt.
The fed objects to be conveyed are loaded on the upper cover rubber and conveyed in a traveling direction of the conveyor belt.
When the objects to be conveyed are fed onto the upper cover rubber of the conveyor belt, the upper cover rubber is subject to impact, and when the surfaces of the objects to be conveyed are sharp, the upper cover rubber sometimes sustains cut damage.
When the objects to be conveyed are loaded on the upper cover rubber and conveyed, the upper cover rubber is subject to wear as a result of the objects to be conveyed sliding on the upper cover rubber.
Thus, in known art, various proposals have been made (see Japanese Unexamined Patent Application Publication Nos. 2001-88922A and 2014-40295A for example) in order to improve the cut resistance of the upper cover rubber, or to improve the wear resistance of the upper cover rubber.
A size and occurrence frequency of the cut damage, a wear amount, and the like occurring in the upper cover rubber significantly change depending on use conditions of the conveyor belt (including types of the objects to be conveyed).
Additionally, even under the same use conditions, degrees of damage vary depending on the rubber physical properties of the upper cover rubber.
Thus, when determining a specification of the conveyor belt (a specification of the upper cover rubber, for example), it has been necessary to determine the specification in each individual case, namely to determine a specific specification, on the basis of the use conditions, which has been a problem in that it requires a great number of man-hours.